1. Field of the Invention
The present invention relates to a liquid applicator usable as a writing tool, a paint applicator, a manicure applicator, or a paste applicator, and a method of making the same. More particularly, the present invention relates to a liquid applicator with a tip having a flattened or rectangular cross section, wherein the liquid can be ink, paint, correction ink, manicure, or paste, depending upon the use of the applicator.
2. Background Art
As a typical example of liquid applicators, felt-tipped pens are known and widely used. In recent years, plastic tips have replaced the felt tips. When viscous liquid such as paint and paste is contained, a valve is used so as to facilitate the flow of the liquid. By reference to FIG. 16 herein, a known liquid applicator will be described.
The illustrated pen includes a cylindrical writing tip 100 of plastic. Whether the tip is felt or plastic, the feature in common with the known applicators is that they commonly use a cylindrical tip.
The writing tip 100 is connected to a cylindrical core 101 through which ink flows from a liquid reservoir (not shown) to the writing tip 100. The core 101 is made of liquid permeable material such as a porous substance or a textile bundle. The writing tip 100 and the core 101 are connected to each other by means of a tip holder 102 which consists of a thick trunk portion 105 and a thin branch portion 103. The trunk portion 105 includes an end portion having an inside diameter to closely receive the core 101. The branch portion 103 has an end portion defining an inside diameter to closely receive the writing tip 100. The tip holder 102 is fabricated by machining (cutting). The writing tip 100 is frictionally held in the branch portion 103, and the core 101 is frictionally held in the tank portion 105, of the tip holder 102.
The core 101 secured to the tip holder 102 is inserted in a bore 108 in the coupler 106. The coupler 106 is secured to a liquid reservoir (not shown). Ink flows from the reservoir to the writing tip 100 through the core 101. The flow of the ink is controlled by a valve (not shown).
In use, the draftsman pushes the writing tip 100 against paper. The core 101 is thrust into the bore 108 and opens the valve (not shown) so as to allow ink to flow to the writing tip 100 through the core 101.
There are other known liquid applicators using a valve in a reservoir--one is shown in Japanese Utility Model Publication (allowed) No. 5-32235 and another is shown in Japanese Utility Model Laid-Open Publication (Kokai) No. 1-84779. These liquid applicators also use a cylindrical tip.
In general, cylindrical writing tips raise no problems when used to write ordinary letters and draw ordinary lines, but they are inconvenient in drawing thick lines and/or painting a relatively large area. Therefore, rectangular writing tips have recently been used wherein "rectangular tip" refers generically to a tip whose cross section is flattened. The advantage of a rectangular tip is that the user can use the side faces, ridges, and corner points of the tip unlike a cylindrical tip. By using the corner points and ridges, thick and thin lines can be freely drawn, and a large area can be quickly painted by using the side faces.
In the liquid applicators using a valve, the tip must be pushed against paper to open the valve, but a problem arises when the rectangular tip is pushed, or if the draftsman has a habit of holding the applicator too strongly. In either case the tip is torqued and tends to rotate. While writing letters or drawing lines, an unexpected rotation of the tip may undesirably change the regularity of lines and letters. Particularly in calligraphy the irregular handwriting may be fatal to the calligraphic beauty.